Hi JonathanM - welcome to Sysnative :)
From the trace I can see 2 long running storport.sys DPCs (a 98.150393ms fragment and a 3.043544ms fragment) on core 1. The DPC routine being called is RaidpAdapterTimerDpcRoutine. Those are long runtimes but they happened back to back and were part of the same "spike" so I'm not convinced they would correspond to the symptoms you described.
On core 0 there are some fairly long running DPCs (8 or 9) which were queued by nvlddmkm.sys which is a Nvidia driver. From slightly less than 1ms to slightly more than 2ms. My guess would be the stuttering is due to the nvlddmkm.sys DPCs although I don't know for sure. Can you confirm you experienced the problem during the trace?
